The present invention relates to devices for loading workpieces into and out of machines which process the workpieces, and the invention specifically provides for a mechanism capable of arranging and handling stacks of such workpieces for being loaded and unloaded relative to a machine which forms the stacks of workpieces into spur or helical gears.
Various types of work-handling and work-transferring devices are known for presenting workpieces to machinery capable of removing stock from the workpieces. The present invention is concerned with the problem of handling stacks of workpieces relative to a gear manufacturing machine which has a capability of processing more than one workpiece, and up to seven or more workpieces, at a time. With such a machine, the problem of loading and unloading is made more difficult by the fact that entire stacks of workpieces must be handled in their movements from a banking area to the work station of the machine and eventually to an unloading station of the machine. In addition, it is desirable that a mechanism for handling stacks of workpieces be adjustable to accomodate different stack thicknesses and different diameters of workpieces in any given stack. Finally, a loading and unloading mechanism for such a machine should allow for manual loading of the work station of the machine in case smaller quantities of workpieces are to be handled or in case of a malfunction of the loading and unloading mechanism.
The present invention solves the problem of handling more than one workpiece at a time with a mechanism having a storage station for holding a quantity of banked workpieces, a transfer arm for receiving discrete stacks of workpieces released from the storage station, and a loading arm for moving stacks of workpieces from the transfer arm to the work station of the machine. In a specific embodiment of the invention, the storage station is constructed with separate channels, arranged in a side-by-side relationship, for receiving a number of workpieces in each channel. The number of channels corresponds to the number of workpieces to be included in each stack, and this provides for an alignment of the banked workpieces in discrete stacks which can be moved, one at a time, from the storage station to the work station of the machine. Movement of separate stacks of workpieces is achieved with a transfer arm which serves to bring the workpieces into correct alignment with one another as the workpieces are released from the storage station. Additionally, the transfer arm clamps and holds each stack in its aligned condition as the stack is moved away from the storage station. The transfer arm is controlled to reorient each stack of workpieces from the position they are in when released by the storage station to a position which corresponds to the orientation required at the work station of the machine. Final movement of the reoriented stack of workpieces is provided for by a loading arm which receives and holds each stack of workpieces discharged from the transfer arm and which then swings the stack of workpieces to a position where the workpieces can be lowered onto a work-holding arbor of the machine. After the workpieces have been processed, they are lifted, again as a discrete stack, from the arbor by the loading arm, after which they are swung to a position for being lowered and unloaded at an unloading station of the machine.
Specific features of the mechanism allow it to handle different thicknesses and diameters of stacks of workpieces. The mechanism is designed to permit ease of access to the work station of the machine in the event that manual loading is required for any reason, and the working elements of the mechanism are relatively simple and easily maintained and adjusted. Control of the mechanism is tied directly to the processing cycle of the gear manufacturing machine and is, therefore, efficient and reliable.